Indoor TV antenna dimensions. Antenna made from beer cans. How to power up an active antenna amplifier

Despite the rapid development of satellite and cable television, reception of terrestrial television broadcasting is still relevant, for example, for places of seasonal residence. It is not at all necessary to buy a finished product for this purpose; a home UHF antenna can be assembled with your own hands. Before moving on to the consideration of designs, we will briefly explain why this particular range was chosen TV signal.

Why DMV?

There are two good reasons to choose designs of this type:

1. The thing is that most channels are broadcast in this range, since the design of repeaters is simplified, and this makes it possible to install larger number unattended low-power transmitters and thereby expand the coverage area.
2. This range is selected for digital broadcasting.

Indoor TV antenna “Rhombus”

This simple, but at the same time, reliable design was one of the most common in the heyday of on-air television broadcasting.

As can be seen from the sketch (B Fig. 1), the device is a simplified version of the classic zigzag (Z-design). To increase sensitivity, it is recommended to equip it with capacitive inserts (“1” and “2”), as well as a reflector (“A” in Fig. 1). If the signal level is quite acceptable, this is not necessary.

The material you can use is aluminum, copper, and brass tubes or strips 10-15 mm wide. If you plan to install the structure outdoors, then it is better to abandon aluminum, since it is susceptible to corrosion. Capacitive inserts are made of foil, tin or metal mesh. After installation, they are soldered along the circuit.

The cable is laid as shown in the figure, namely: it did not have sharp bends and did not leave the side insert.

UHF antenna with amplifier

In places where a powerful relay tower is not located in relative proximity, you can raise the signal level to an acceptable value using an amplifier. Below is circuit diagram device that can be used with almost any antenna.

List of elements:

• Resistors: R1 – 150 kOhm; R2 – 1 kOhm; R3 – 680 Ohm; R4 – 75 kOhm.
• Capacitors: C1 – 3.3 pF; C2 – 15 pF; C3 – 6800 pF; C4, C5, C6 – 100 pF.
• Transistors: VT1, VT2 – GT311D (can be replaced with: KT3101, KT3115 and KT3132).

Inductance: L1 – is a frameless coil with a diameter of 4 mm, wound with copper wire Ø 0.8 mm (2.5 turns must be made); L2 and L3 are high-frequency chokes 25 µH and 100 µH, respectively.

If the circuit is assembled correctly, we will get an amplifier with the following characteristics:

• bandwidth from 470 to 790 MHz;
• gain and noise factors – 30 and 3 dB, respectively;
• the value of the output and input resistance of the device corresponds to the RG6 cable - 75 Ohm;
• the device consumes about 12-14 mA.

Let us pay attention to the method of power supply; it is carried out directly through the cable.

This amplifier can work with the simplest designs made from improvised means.

Indoor antenna made from beer cans

Despite the unusual design, it is quite functional, since it is a classic dipole, especially since the dimensions of a standard can are perfect for the arms of a UHF vibrator. If the device is installed in a room, then in this case it is not even necessary to coordinate with the cable, provided that it is not longer than two meters.

Designations:

• A - two cans with a volume of 500 mg (if you take tin and not aluminum, you can solder the cable instead of using self-tapping screws).
• B – places where the cable shielding is attached.
• C – central vein.
• D – place of attachment of the central core
• E – cable coming from the TV.

The arms of this exotic dipole must be mounted on a holder made of any insulating material. As such, you can use improvised things, for example, a plastic clothes hanger, a mop bar or a piece of wooden beam of the appropriate size. The distance between the shoulders is from 1 to 8 cm (selected empirically).

The main advantages of the design are fast production (10 - 20 minutes) and quite acceptable picture quality, provided there is sufficient signal power.

Making an antenna from copper wire

There is a design that is much simpler than the previous version, which only requires a piece of copper wire. We are talking about a framework loop antenna narrow range. This solution has undoubted advantages, since in addition to its main purpose, the device plays the role of a selective filter that reduces interference, which allows you to confidently receive a signal.

For this design, you need to calculate the length of the loop; to do this, you need to find out the frequency of the “digit” for your region. For example, in St. Petersburg it is broadcast on 586 and 666 MHz. The calculation formula will be as follows: L R = 300/f, where L R is the length of the loop (the result is presented in meters), and f is the average frequency range, for St. Petersburg this value will be 626 (the sum of 586 and 666 divided by 2). Now we calculate L R, 300/626 = 0.48, which means the length of the loop should be 48 centimeters.

If you take a thick RG-6 cable with braided foil, it can be used instead of copper wire to make a loop.

Now let's tell you how the structure is assembled:

• A piece of copper wire (or RG6 cable) with a length equal to L R is measured and cut.
• A loop of suitable diameter is folded, after which a cable leading to the receiver is soldered to its ends. If RG6 is used instead of copper wire, then the insulation from its ends is first removed, approximately 1-1.5 cm (the central core does not need to be cleaned, it is not involved in the process).
• The loop is installed on the stand.
• An F connector (plug) is screwed onto the cable to the receiver.

Note that despite the simplicity of the design, it is most effective for receiving “digits”, provided that the calculations are carried out correctly.

Do-it-yourself MV and UHF indoor antenna

If, in addition to UHF, there is a desire to receive MF, you can assemble a simple multiwave oven, its drawing with dimensions is presented below.

To amplify the signal in this design, a ready-made SWA 9 unit is used; if you have problems purchasing it, you can use homemade device, the diagram of which was given above (see Fig. 2).

It is important to maintain the angle between the petals; going beyond the specified range significantly affects the quality of the “picture”.

Despite the fact that such a device is much simpler than a log-periodic design with a wave channel, it nevertheless shows good results if the signal is of sufficient power.

DIY figure eight antenna for digital TV

Let's consider another common design option for receiving “digits”. It is based on the classic scheme for the UHF range, which, because of its shape, is called “Figure Eight” or “Zigzag”.

Design dimensions:

• outer sides of the diamond (A) – 140 mm;
• inner sides (B) – 130 mm;
• distance to the reflector (C) – from 110 to 130 mm;
• width (D) – 300 mm;
• the pitch between the rods (E) is from 8 to 25 mm.

The cable connection location is at points 1 and 2. The material requirements are the same as for the “Rhombus” design, which was described at the beginning of the article.

Homemade antenna for DBT T2

Actually, all of the examples listed above are capable of receiving DBT T2, but for variety we will present a sketch of another design, popularly called “Butterfly”.

The material can be used as plates made of copper, brass, aluminum or duralumin. If the structure is planned to be installed outdoors, then the last two options are not suitable.

Bottom line: which option to choose?

Oddly enough, the simplest option is the most effective, so the “loop” is best suited for receiving a “digit” (Fig. 4). But, if you need to receive other channels in the UHF range, then it is better to stick with “Zigzag” (Fig. 6).

The antenna for the TV should be directed towards the nearest active repeater, in order to select the desired position, you should rotate the structure until the signal strength is satisfactory.

If, despite the presence of an amplifier and reflector, the quality of the “picture” leaves much to be desired, you can try installing the structure on a mast.

In this case, it is necessary to install lightning protection, but this is a topic for another article.

The modern market offers a huge range of antennas for receiving terrestrial television. There are two main types of these products that allow you to receive meter and decimeter radio waves. They can also be divided according to the place of use into outdoor and indoor. Fundamentally, they are not much different. Here, first of all, the emphasis is on size and maintaining the necessary parameters under the influence of weather conditions. In this article we will discuss existing species of these products, let’s look at what parameters they have and how to conduct testing. And for those who like to tinker, we’ll tell you how to make a decimeter antenna with your own hands.

What's the difference?

Let's try to explain in a nutshell how to determine what type of product is in front of you. The UHF antenna looks like a ladder. Install them parallel to the ground. Meter ones are crossed aluminum tubes. Appearance both types are shown in the photo below. There are also combined antennas, when both the “ladder” and cross tubes are combined.

The problem of choice

It would seem that everything is simple. However, the buyer is faced with the question of how to choose the right device and what parameters to pay attention to. In general, it is best to test TV antennas directly in the conditions in which they will operate. The passage of a radio signal is often individual for a particular area. Thus, a product shows the same results in laboratory conditions, but completely different results in the field. There are certain tactics that allow you to test both meter and decimeter TV antennas. However, when choosing such a product in a store, we do not have the opportunity to conduct full testing. Not a single seller will agree to give us several different antennas to test. In this case, you have to trust the characteristics of these products. And hope that the selected antenna will perform its functions according to the passport data, and not real conditions.

Basic parameters

A decimeter antenna is characterized primarily by its radiation pattern. The main parameters of this characteristic are the level of the side (auxiliary) lobes and the width of the main lobe. The width of the diagram is determined in the horizontal and vertical planes at a level of 0.707 from highest value. So, according to this parameter (the width of the main lobe), diagrams are usually divided into non-directional and directional. What does this mean? If the main lobe has a narrow shape, then the antenna (decimeter) is directional. Next important parameter is noise immunity. This characteristic primarily depends on the level of the back and side lobes of the diagram. It is determined by the ratio of the power released by the antenna, subject to a consistent load at the time of receiving a signal from the main direction, to the power (with the same load) when receiving from the side and rear directions. First of all, the shape of the diagram depends on the number of directors and the design of the antenna.

What does the term “wave channel” mean?

TV antennas of this type are very effective directional receivers of radio signals. They are widely used in areas of clearly weak television airwaves. The antenna (decimeter) of the “wave channel” type has high gain and has good directivity. In addition, these products have relatively small dimensions, which (on par with high level reinforcement) makes it very popular among residents of holiday villages and other settlements remote from the center. This antenna also has a second name - Uda-Yagi (named after the Japanese inventors who patented this device).

Operating principle

A decimeter antenna of the “wave channel” type is a set of elements: passive (reflector) and active (vibrator), as well as several directors, which are installed on a common boom. The principle of its operation is as follows. The vibrator has a certain length, it is located in the electromagnetic field of the radio signal and resonates at the frequency of the received signal. In it, an electromagnetic field is induced on each passive element, which also leads to the occurrence of EMF. As a result, they re-emit secondary electromagnetic fields. In turn, these fields induce additional EMF on the vibrator. Therefore, the dimensions of the passive elements, as well as their distances from the active vibrator, are chosen such that the EMF induced by them due to secondary fields is in phase with the main EMF, which is induced in it by the primary electromagnetic field. In this case, all EMFs are summed up, which increases the efficiency of the design compared to a single vibrator. Thus, even an ordinary room can provide stable signal reception.

The reflector (passive element) is installed behind the vibrator 0.15-0.2 λ 0. Its length should exceed the length of the active element by 5-15 percent. Such an antenna produces a one-way directional pattern in the vertical and horizontal planes. As a result, the reception of reflected signals and fields that come from the back of the antenna is significantly reduced. If necessary, receive a television signal on long distances, as well as in difficult conditions, in the presence of a lot of interference, it is recommended to use a three or more element antenna, which consists of an active vibrator, one or more directors and a reflector.

Direct and reflected signals

In an article devoted to a wave receiving device (“Tele-Sputnik” No. 11 for 1998), it was noted that in the case when the signal source is not a standard (that is, not laboratory) generator and emitting antenna, and the signal is broadcast TV tower, weather conditions play a significant role, as does the location where the receiver is installed. This especially affects the operation of UHF products. This is explained by the fact that in the decimeter range there is less, and accordingly, rounding of obstacles is much worse, and any reflections of the signal play a role important role as the received image. In particular, even the wall of a house can be a wave reflector. So, in conditions where there is no direct visibility, this property can be used - to receive the reflected signal. However, its quality will be lower than that of the direct one. If the level of the broadcast signal is high, but there is no line of sight, then you can use the reflected wave. In fact, an indoor decimeter antenna works precisely on this principle. After all, it is difficult to catch a direct wave in a room if the windows face reverse side. Therefore, if you try, you can always find a point where the received signal will be higher. But in the case of direct visibility, any reflected interference will spoil the received picture.

A technique that allows you to compare antenna parameters

In order to test receiving devices, they need to create the same conditions:

1. Select the installation location where your antenna will operate. You can use a balcony, roof or mast. The main thing is that both the height and the location are the same for all products.

2. The direction to the source of the broadcast signal should be maintained with an accuracy of three degrees. To do this, you can make a special mark on the mounting pipe.

3. Measurements should be carried out under the same weather conditions.

4. The cable connecting the antenna and the TV must have the same resistance and length. It is best to use one wire, changing only the receivers.

Testing should only be carried out on products of one type. For example, an indoor UHF antenna should not be compared with an outdoor one or with meter receivers. It should be understood that field tests may produce results that differ significantly from laboratory tests.

UHF antenna for digital television

IN lately The media are increasingly talking about the need to switch to digital television. Many have already done this, and some are still thinking about it. So far, the signal is broadcast in both modes. However, the quality leaves much to be desired. In this regard, people are interested in what decimeter antennas can be used for T2. Let's look at this issue. Essentially, digital television broadcasts on a UHF channel. So a standard UHF antenna may be suitable for receiving it. You can often see receivers in stores that indicate that they are intended for digital television. However, this is a marketing ploy that allows you to sell a standard decimeter antenna for more than it costs. When purchasing such a product, you will not have a guarantee that it will provide best reception than something that is already in your home and has been working for more than one year. As we said earlier, the quality depends mainly on the level of the broadcast signal and line of sight conditions. However, it should be borne in mind that in most cities, significantly more powerful generators are used for transmitting digital television than for analogue. This is done in order to speed up the transition to the new standard. After all, the audience wants to see clear image, not “snow” on the screens. Therefore, if a receiver is displayed in a window that says “ UHF antenna for DVB T2”, please know: this does not mean that this is some kind of special product. It’s just that a not entirely honest seller wants to profit from an uninformed buyer. You should also know that the transition program to the new standard provides for the creation of advisory centers. In them you can get comprehensive information on any issue related to digital television. All consultations are provided free of charge. In some cities this equipment is in test mode, so the signal may be unstable or weakened. Don’t worry, the center staff will always tell you how to solve the problem with signal reception quality.

DIY decimeter antenna

The length of UHF waves falls within the range from 10 cm to 1 m. Their name comes from this feature. At this frequency they propagate predominantly in a straight line. They practically do not bend around obstacles and are only partially reflected by the troposphere. In this regard, long-distance communication in the UHF range is very difficult. Its radius does not exceed one hundred kilometers. Let's look at a couple of examples of how to make a decimeter antenna at home.

First option homemade receiver television broadcasting will, so to speak, be assembled on the knee from scrap materials. UHF channels are located in the range from 300 MHz to 3 GHz. Our task is to produce an antenna that will operate precisely at these frequencies. For this we need two 0.5 liter beer cans. If you use a larger capacity, the received frequency will decrease. For installation you will need some kind of frame; you can use a board 10 cm wide. You can also use a regular wooden hanger, in which case the resulting antenna can be hung on a nail in any convenient place in the room. In addition to the frame and cans, you need to prepare a pair of self-tapping screws, tools, a coaxial cable, a connector, terminals, and insulating tape. We put a television connector on one end of the cable and solder it. We insert the second end into the terminal block. Next, we attach the terminals to the necks of the cans with screws. The wires should fit snugly to the metal. Now let's start assembling the antenna itself. To do this, we secure the jars on a horizontal crossbar with their necks facing towards each other. The distance between them should be 75 mm. You can use insulating tape to secure the cans. That's it, the antenna is ready! Now we need to find a place for stable reception of a television signal and hang our “hanger” in this place.

Receiver for digital television

This section is intended for people who do not want to use a regular (analog) product, but want a special UHF antenna to be used for the new format. Do it yourself receiver It is also easy to assemble. To do this, we will need a square wooden (or plexiglass) frame with a diagonal of 200 mm and regular cable RK-75. The option presented to your attention is a zigzag antenna. It has proven itself well when working in the digital television reception range. Moreover, it can be used in places where there is no direct visibility to the signal source. If your broadcast is weak, you can connect an amplifier to it. So let's get to work. We strip the end of the cable by 20 mm. Next, we bend the wire into a square shape with a diagonal of 175 mm. We bend the end outward at an angle of 45 degrees, and bend the second stripped end to it. We connect the screens tightly. The stripped central core hangs freely in the air. On the opposite corner of the square, carefully remove the insulation and screen over a 200 mm area. This will be the top of our antenna. Now we connect the resulting square with a wooden frame. At the bottom, where the two ends are connected, copper staples made from thick wire should be used. This will ensure better electrical contact. That's all, the decimeter antenna for digital television is ready. If it will be installed outside, you can make a plastic case for it, which will protect the device from precipitation.

Bread and circuses – that’s what the Roman poet and satirist Juvenal said, and in some ways he was absolutely right. Modern society, and in particular modern man, can no longer do without pretentious pictures, shocking videos, exciting films, and comedy skits. One of these “elements” that can provide us with access to the world of entertainment is television. But even here it is not enough to have a TV, it also needs to have an antenna. After all, without a good antenna, radio waves are as difficult to catch as a fish on a hook without bait. What an antenna is needed for is not only prosaic to say, especially since we have practically already mentioned it, but more disrespectful to our reader. So, skipping the description of the purpose of the antenna, let's proceed to the description of its creation. We wanted to talk about how to make an antenna with your own hands in this article.

Below is one of the simplest and most importantly, available ways allowing you to make an indoor antenna for your TV. It is made from practically nothing, or rather - 2 beer cans, self-tapping screws, a coat hanger, a wire and a plug.

DIY TV antenna made from beer cans

So, we need a couple of beer cans, a soldering iron, a TV cable, solder and a few other things. More on this in the course of our story.

Here we need to know in what order and what to do to get the much desired television antenna. If we talk about the requirements for the materials used to make the antenna, then first of all, buy a good television cable. A good TV cable requires a resistance of 75 ohms per meter, a strong central core and dense continuous double shielding. How much cable to buy depends on where the antenna is located, but know that the longer the cable, the more “useful” signal will be canceled out in it. (the rule clearly works for microwave waves). For UHF it also works, but is not so critical.

So, we make a cut for the plug and install it on the wire.

Next, let's start working with the second end TV cable. Here you need to bring out 2 cable conductors, one from the very edge, and the second after about 10-15 cm. The first conductor is considered the core, the second is the shielding. Here you will also need to be careful not to cut through extra layers of insulation and conductors. As a result, the efficiency of the antenna and the clarity of reception of television channels will depend on the quality of each and the total of all work - remember this. The photo below shows how the first and second conductors are removed from the cable. The top insulation is removed at a distance of 10-15 cm from the edge of the cable.

Now about beer cans. We don't know what kind of beer you can afford and like, but you need more cans. We repeat, not many, but big ones. 0.75 is good, but liter ones are even better. It’s difficult to say anything about large 5 liter beer kegs. This will probably go beyond the “framework” of an indoor antenna. After drinking beer, rinse the jars in water and dry them so that the aroma of an intoxicating drink does not emanate from them. Such a smell will not attract radio waves, but it certainly will attract flies.
Now we take the cable that we prepared earlier. Using small self-tapping screws, screw one conductor to the end of the first can, the other to the end of the second. To improve contact between the can body and the screw, use solder. Fill any possible gaps to improve contact.

Now our antenna is almost ready, we don’t have enough frame to base the cans together and to attach the antenna to something. In our case, the frame was coat hangers. For this there are all the criteria "FOR". Low price, availability, proper rigidity and size. Yes, there is also a hook to hang everything at once in the chosen place.
So, we place the jars on one straight line, so that they are symmetrical about the center. “Play around” a little with the distance between them, since the quality of signal reception will depend on this. You can secure the cans with tape or tape. The approximate distance for the cans on the antenna is about 75 mm.

As a result, we get a simple but functional thing - an indoor television antenna made from beer cans. Of course, such an antenna can only operate in an area with reliable television signal reception. This is not an antenna for receiving a signal 20 km from the city, it is just something that will slightly make the reception more reliable, but not ideal.
Professionals, perhaps, are already laughing sarcastically at this article and the antenna, because in fact, a television antenna requires a strict and accurate calculation of its elements, depending on the received wavelength. They are absolutely right about this. But this calculation is not always accessible to the average person, which encourages him to undertake similar adventures in making antennas, such as in particular for the antenna shown here, from beer cans.
Next, we will consider a more serious option. First of all, its big advantage is that it will tell you how to make an antenna according to all the rules, taking into account physical features propagation of radio waves.

Radio waves received by a TV antenna

Since we have climbed so far, it is necessary to at least talk about the basics, because how could it be otherwise!? Radio waves of television channels analog signal propagate in the range of meter (MV) and decimeter waves (UHF).
In essence, this is the same thing, except that MV and UHF waves propagate at different radio wave frequencies. Meter waves are from 1 to 21 channels, and UHF from 21 to 40 channels. It is important to note here that depending on the wavelength, it will be necessary to use an appropriate antenna for VHF or UHF waves. It is also necessary to say that antennas are available for both indoor and outdoor use. Let's consider both options.

Do-it-yourself indoor TV antennas (MV and UHF)

MV indoor antenna

The voltage of magnetic waves indoors is much less than outside. Therefore, it makes sense to use indoor antennas only in the immediate vicinity of the television center. So the simplest indoor antenna can be made from an electric wire or any other insulated conductor. An insulator is installed in the center of the antenna. Two conductors are attached to it using fasteners (bolt - nut). The ends of the conductors are stretched so that they are straight, like strings or rods.

The total length of the conductors, the two arms of the antenna, is taken according to the wavelength and the received channel. This data can be taken from the table.

If you choose the length of the antenna conductors according to the television channel you are watching, it will be much more effective than beer cans.
Next, we will present another option for an indoor TV antenna that you can make yourself. This is a UHF antenna. No matter what UHF channels are practically not used, yet broadcasting is still sometimes carried out somewhere. This means that we also cannot ignore this topic. Here is an example of a UHF antenna.

UHF indoor antenna

The mounting wire used, referred to as KPTA-1, serves to increase the antenna's noise immunity. To do this, as you can see, at a distance of 140 mm from the edge of the cable, the insulation was stripped to the screen and this mounting wire - a loop - was soldered. You can use another wire with a cross section of 0.35 mm.
The frequency of received radio waves from this antenna will be from 470 to 630 MHz, that is, UHF waves.
All antenna elements are mounted on a stand, which is a dielectric.

Do-it-yourself outdoor TV antennas (MV)

Antenna - half-wave linear vibrator

This outdoor antenna designed to receive television waves near the city 20-30 km. In fact, this is an analogue of the simplest indoor antenna, which we already talked about a little earlier, except that it is adapted for the street.
So, as we already understood, the antenna must have certain dimensions, which will affect the reception of television radio waves. The dimensions will depend on which channel you are going to watch. All dimensions for the antenna can be found in the table.

Rice. 1. Antenna - half-wave linear vibrator (It is a simple television antenna)

The input impedance of the linear vibrator (antenna) is 73 Ohms. The bandwidth of a linear vibrator depends on the outer diameter of its tubes and increases as the latter increases.
You should not choose a D greater than 30 mm, since with its further increase the image quality does not noticeably improve, and the weight and dimensions of the antenna increase.
In table 1 shows the dimensions of the linear vibrator elements. The gap A between the ends of the tubes is 50-70 mm.

The antenna is connected to a TV with an unbalanced 75-ohm input using coaxial cable(RK-75-4-15, RK-75-9-12, etc.) The cable is connected to the antenna through a special balun (see Fig. 2).

The required dimensions of the elements of matching devices are selected according to table. 2.

The antenna is made of steel, aluminum or brass tubes and metal strips. To attach antenna tubes to a metal or wooden mast, porcelain insulators and textolite are used.
An antenna - a half-wave vibrator is used in close-range reception conditions, we have already talked about this. (20-30 km). This antenna option is, of course, more labor-intensive than an indoor antenna, but its efficiency will be much higher. To receive television broadcasts far from the city, or rather from the transmitter, a “wave channel” antenna is used.

Do-it-yourself "wave channel" antenna MV and UHF calculation and diagram

At large distances from the transmitter, that is, the television center, this is about 40-90 km, antennas of the “wave channel” type are used. Such antennas have very good gain, but require strict directionality. If you use such an antenna in populated areas, this will reduce interference from adjacent sources, thereby improving the image.
The antenna “wave channel” in its structure consists of an active loop and linear vibrator. We talked about the linear vibrator in the previous paragraphs. The antenna size is selected based on signal amplification considerations; the further away, the more complex the antenna will be. Also, the number of directors can improve the receiving properties of the antenna by changing its sensitivity to the directionality of the transmitter.
however, a large increase in the number of directors leads to a decrease in bandwidth. Here you need to find " golden mean" So on MV channels, 3, 5 and 7 element antennas are used.

The geometric dimensions of such “wave channel” antennas are given in the table. At the same time, for channels 1-5, tubes measuring 18 mm are used in the design, and for channels 6-12, 12 mm.

But for UHF waves a 16 element antenna is used. The diameter of the tubes is 6-10 mm, and for the boom 14-16 mm.

The dimensions for it are also given in the table.

After the antenna is ready, it will be necessary to stretch the television, antenna cable from it to the TV. About this in the article "

Digital television T2 is gaining momentum in popularity. And this is natural, analogue television is being replaced by digital television and this is an irreversible process. Moreover, in the near future, analogue broadcasting will be stopped altogether. What should users who have TVs without a T2 receiver and no cable television do? The answer is simple - buy a T2 set-top box. Today, the price of T2 consoles has dropped greatly and does not look exorbitant. The advantages are quite big: you have many channels in digital quality, no monthly fee, with minimum costs and without buying a new TV. Only by comparing the quality of digital and analog TV will you never regret your choice.

Quite a lot has been written on the choice of T2 receivers. Moreover, new models are constantly being released. I would advise taking an inexpensive, but new model, after reading reviews on online store sites. As a rule, any receiver works, but the antenna is of great importance. Even if you are close to a TV tower, but are blocked by high-rise buildings, etc. - and this is almost always the case, then a good antenna is the key to a problem-free (and most importantly, stress-free) quality reception maximum quantity digital channels TV.

But an expensive antenna is not always a good antenna. Especially if you are 50 km or more away from the TV tower. Stores offer “special” antennas for T2. In fact, there is nothing “special”; you need a good antenna for the DCM range. If you still have an old DCM antenna, try connecting it first. Widespread "Polish" antennas are not suitable for receiving T2 digital channels.

I offer a proven option that is simple, but at the same time has proven itself, homemade antenna for T2. The shape of the antenna is not new; it has been used for a long time and when receiving DCM analog television, but the dimensions are optimized for receiving T2 digital channels.
It is worth noting that the Internet offers large number options for homemade antennas for T2: from beer cans, from antenna cable, converted Polish, etc. This is for the completely lazy, and you shouldn’t expect quality from such antennas.

So. The long-known “figure eight” was taken as the shape of the antenna. The antenna body is made of any conductive material of suitable cross-section. This can be copper or aluminum wire with a thickness of 1 to 5 mm, a tube, strip, busbar, corner, profile. Copper is, of course, preferable. I used 6mm diameter copper tube. Good option and copper wire. I just had such a pipe.

Dimensions

The outer side of the square is 14 cm, the inner side is slightly smaller - 13 cm. Due to this, the middle of the two squares does not converge, leaving a gap of about 2 cm.
In total, you will need a tube, wire or other material 115 cm long (with a small margin).

The first section is 13 cm + 1 cm for a loop (for strength), if made of wire, or riveted for overlapping soldering for a tube. The second and third - 14 cm each, the fourth and fifth - 13 cm each, the sixth and seventh - 14 cm each, and the last eighth - 13 cm + 1 cm, again for connection.

We strip the ends by 1.5 - 2 cm, twist the two loops behind each other, and then solder the joint. This will be one cable connection pin. After 2 cm another.

From a copper tube it looks like this

It’s a little more difficult to bend the tube, but we don’t need much precision. Minor flaws in the shape do not affect the performance of the antenna. But the fact that the conductor area increases is a plus. Well, the conductivity of copper is higher than that of aluminum and, especially, steel. The higher the conductivity, the better reception antennas.

The connection prepared for soldering is first riveted and cleaned. For soldering you need to use a powerful soldering iron (from 150 W). Simple amateur radio at 30 watts. don't solder. You can use acid for soldering.

Check the geometry again and solder the connection

If you are not particularly bothered by the aesthetic appearance, you can simply attach the antenna to a glazing bead or any other available holder. This antenna was located in the attic, so the simplest mounting method was used - electrical tape. If the antenna will be placed outdoors, take care of more aesthetic and reliable mounting.

This is a version of the T2 antenna made of aluminum wire with a diameter of 3 mm. Secure with one screw to the window. The distance to the TV tower is about 25 km. True, the 6th floor, I didn’t check lower, but in these conditions the signal level is 100% and the quality is 100%. The cable is old, 12 meters to the TV. Receives all 32 channels. At first I was worried that it wasn’t copper, but as it turned out, it was in vain. Everything worked out perfectly on ordinary aluminum wire (which happened to be available). That is, if you have a reliable reception zone, then you don’t have to bother and feel free to use aluminum (I don’t know, maybe steel will do).

This antenna does not use any amplifiers. It is very easy to set up - just turn maximum level signal and quality on your tuner channels. Check other channels and fix the antenna. If reception is poor, you can experiment with not only rotating, but also changing location and height. Very often, the signal can be many times stronger if the antenna is shifted only 0.5-1 m to the side or in height. Good luck - the antenna has been tested - 100% functional and better than at least half, or even more, of purchased antennas, where they save on everything and sell garbage for good money.

When arranging a summer cottage, we try to make it as comfortable as possible for relaxation. This means that over time it acquires the amenities that we are so accustomed to in everyday life - water supply, heating and, of course, electricity. And where the latter exists, sooner or later television will definitely appear. But how, you ask, can you carry it out at your dacha if purchasing an antenna, which, by the way, is not cheap at all, is not included in the plan? personal budget? Yes, very simple! A few basics of radio electronics, a couple of pieces of iron and a minimal soldering kit and now, having thoroughly tired of the garden, you settle down on the country terrace to watch the evening news block.

Radio electronics and television broadcasting: simply about the complex

The most important thing for any antenna is its ability to interact with a signal distributed over the air.

Currently, TV broadcasting is carried out in one single band - the decimeter band, and television transmitters cover almost the entire more or less populated territory. This makes it possible to “catch” a TV signal anywhere.

But for this you will have to take into account a few simple nuances.:

Based on this, among all the diversity television antennas The most accessible types for self-production will be the following:

1. All-wave (frequency independent)

It does not have high parameters, but it is the simplest and cheapest to manufacture - its basis is a metal frame, and ordinary beer cans or other tin containers act as receivers.

1. Log-periodic range

Such an antenna can be compared to a fishing net, which sorts the prey during catching. This type antenna systems also has a simple design, but provides higher parameters than the all-wave unit.

1. Decimeter zigzag

For the decimeter range, the dimensions and complexity of the design of such an antenna are significantly simplified, and it can operate in almost any reception conditions.

Subtleties of making television antennas

The antenna elements through which the useful signal currents pass are always connected by soldering or welding. But if the device is placed outdoors, for example, on the roof of a country house, such contacts will soon be corroded by corrosion.

If we are talking about homemade antenna to give, strive for perfect quality contacts are not worth it - if they rust or burst, then at least not soon. But it is desirable that there be as few connections as possible in the antenna design, which will ensure stable and fairly clean reception.

The braid and core of coaxial cables are now made from inexpensive alloys that are corrosion resistant. Unlike classic copper, they are difficult to solder. Therefore, you need to be careful not to burn the cable.

To make an antenna and its cable connection, it is advisable to use:

Aluminum wire should not be used to make antenna elements - it will oxidize very quickly and lose its ability to conduct electrical signal. In the best possible way Copper or cheaper brass is suitable for this.

The antenna reception area should be as large as possible. To do this, several metal rods made of the same metal should be symmetrically attached to the screen - a frame that filters out ethereal and electrical noise.

Buying a simple signal amplifier connected directly to the antenna will solve the problem with a weak and dirty signal.

As a result, the system will provide normal reception power. All you need to do is take the antenna to the roof of the country house and point it towards the nearest television tower.

DIY frequency independent antenna

The simplest all-wave unit is a pair of metal plates mounted on a wooden slats and connected by several turns of copper wire of any diameter. The width of such an antenna should be equal to its height, and the opening angle of the panels should be 90 degrees. It is not necessary to solder the wire to the zero potential point of the all-wave oven - it is enough to ensure that it is securely fastened.

The frequency-independent antenna is capable of receiving both meter and UHF signals from almost any direction. The disadvantage of this option is the unity gain and zero gain - an indicator of the ratio of the signal power received at the main lobe of the antenna to the sum of the interference power at the frequency received by the other elements. That is why the Vsevolnovka is not suitable for receiving a TV signal in an area with strong interference or where broadcast signal too weak.

To make your own frequency independent antenna you will need:

• antenna cable;
• several tin cans;
• self-tapping screws;
• plug;
• insulating tape;
• screwdriver;
• wooden slats;
• copper wire.

The cans are secured to the rail (mast) using electrical tape at a distance of about 7 cm from each other.

Self-tapping screws are screwed into them, and the stripped ends of the antenna cable are screwed to the protruding ends of them. The latter is fixed to the rail and laid along the external building structures of the country house to the place where you plan to put the TV.

You can improve the design of the all-wave unit by adding a few more sections from tin containers. Afterwards, all that remains is to securely secure its mast in a vertical position, connect it to the TV and set up the tuner.

Another option for an all-wave antenna designed to receive a meter signal is a fan vibrator, which is popularly called a slingshot antenna.

Manufacturing a log-periodic television antenna

The “speech therapy” antenna is a receiving line (a pair of metal tubes) with halves of linear dipoles perpendicularly connected to it - pieces of conductor with a diameter of a quarter wave of the working signal. The length and distance between the latter varies exponentially.

To manufacture a log-periodic antenna, it is necessary to perform a number of calculations:

1. The calculation of the length of the dipoles begins with the second longest one.
2. Taking the reciprocal of the progression index, the length of the longest dipole is calculated.
3. Next, it remains to calculate the shortest - the first - dipole, and then, based on the selected frequency range, the length of the “zero” dipole is accepted.

To achieve maximum power reception between dipoles should be a distance of 0.03-0.05 wavelengths, but not less than double the diameter of any of them.

The length of the finished LP antenna is about 400 mm. The diameter of the base of the LP antenna should be 8-15 mm, and the gap between their axes of the receiving line should be no more than 3-4 dipole diameters.

For normal operation For LP antennas, you need to select a high-quality and fairly thick (about 6-8 mm in sheath) coaxial cable. Otherwise, you will not be able to compensate for the attenuation of decimeter waves, as a result of which the television tuner will be unable to sense the signal.

The cable to the receiving line cannot be secured from the outside, as this will sharply reduce the quality of signal reception.

When installing such an antenna, you need to ensure its wind resistance, and if you use a metal pipe as a mast, you need to install a dielectric insert - a wooden block - at least 1.5 cm long between it and the receiving line.

You can improve the design of an LP antenna by installing linear or fan-shaped meter field hangers on it. This system is called “delta”.

Delta antenna circuit

Zigzag antenna for a summer residence

The Z-antenna system with a reflector provides almost the same TV signal reception parameters as the LP antenna. However, its main petal is horizontally twice as long. This makes it possible to catch a signal from different directions, which is especially important for rural areas.

The decimeter zigzag antenna has small dimensions, but its operating range is practically unlimited. The material for the manufacture of such a system is a copper tube or aluminum sheet about 6 mm thick. If you choose the latter, you won’t be able to solder it with regular solder or flux - in this case, the fastenings are made with bolts. For outdoor installation, such an antenna will be ready only after sealing the connection points with silicone.

Design zigzag antenna consists of the following elements:

• barbell;
• wire cloth;
• metal plates for fastening the canvas;
• cross slats;
• dielectric plates and gaskets;
• mounting plate;
• feeder line;
• power plate.

Any of them can be made with your own hands from scrap materials or purchased at the nearest radio electronics store.

The sides of the Z-antenna are made of solid metal or in the form of a mesh covered with a sheet of tin. When laying coaxial cable along the body of the antenna, sharp bends should be avoided. To do this, it is enough to reach the side capacitive insert and not let it go beyond it. At the point of zero potential, the cable braid is carefully soldered to the fabric.

TO this class We can also include such types of antennas as ring and reflector, which are also not particularly difficult to manufacture.

Options for making television antennas yourself in the photo

There are other types of antennas suitable for self-production - wave, “Polish”, simple frame and even primitive satellite. But no matter which option you choose, proper calculation of the parameters is required. The technique can be found in the technical literature on radio electronics. However, it is much easier and simpler to ask advice from those who already have experience in making this kind of antennas.

Making your own antenna for a summer house on video